An airbag system is known as an example of a passenger protecting device, and a pop-up hood system is known as an example of a pedestrian protecting device.
An airbag system that performs deployment control on an airbag during a collision is constituted by an airbag control ECU (Electronic Control Unit) disposed in a substantially central portion of a vehicle, and an airbag for protecting a passenger during a head-on collision. Other airbags include a side airbag or a curtain airbag for protecting the passenger during a side-on collision, and so on.
Meanwhile, a pop-up hood system for performing deployment control on a pop-up hood during a collision with a pedestrian includes a pedestrian protection control ECU disposed in the substantially central portion of the vehicle, and a pop-up hood for mitigating an impact on the pedestrian during the collision with the pedestrian. Other mechanisms for protecting pedestrians include a pedestrian protecting airbag, an airbag for preventing a pedestrian from rolling on a body, and so on.
Incidentally, a body velocity may be used as an activation condition in the passenger protecting device and pedestrian protecting device described above.
When calculating the body velocity, a wheel velocity substantially matches the body velocity during a normal run, but when a tire spins, locks, or the like, a difference occurs between the wheel velocity and the body velocity, and therefore the wheel velocity must be corrected in order to calculate the body velocity accurately.
Patent Document 1, for example, discloses a known method of estimating a body velocity by correcting a wheel velocity, in which an acceleration measured by an calculation from a wheel velocity is corrected downward when the acceleration exceeds a predetermined upper limit value (or lower limit value), and a value obtained by integrating the corrected acceleration is output as a corrected wheel velocity (=the body velocity).